You can not change a 72 DPI image to 300 DPI without the dimensions of the image shrinking drastically. The image needs to be rendered out at a massive resolution set to 300 DPI That's one of the reasons Bryce has a render to disk option Here's a quick run down on how to set up and rendering to disk ( in Bryce ) First you need to set the document aspect ratio, the dimensions you stated are 24X36 In. The document does not need to be as big but the aspect ratio needs to conform to the same dimensions. So go to File/Document Set-up, On the Document Set-up Menu type in a value of 2 : 3 in the Document Aspect Ratio fields, then type in 400X600 in the Document Resolution fields. This should give you a document with the correct ratio and a manageable mostly viewable work space. Do a fast test render to see if the scene fits in these dimensions. ( set to no AA if need be to speed the render up ) Correct any camera setting to fit the scene if need be. Set the render options to what you want AA, premium or what not. The Render to Disk option is located on the File Menu / Render Tab. When the menu opens first type in 300 in the DPI option Then type in the dimensions in the inch options 24X36 ( bottom fields ). Exit the menu by hitting the check. In the Save dialog, locate a place to save, name and set the file type to one with no compression ( BMP or Tiff ). Hit OK and the render starts. If you stop the render an option will appear to resume or cancel the render. ( this type of rendering can not be stop, then restarted at a latter time or day ) Be prepared for a render of this size to take awhile ( possible even days ). Talk to the printer people ( or who ever is publishing the piece and ask them what file type they prefer. You may not need to convert the image to EPS in Photoshop. But if you do simple open the image in Photoshop and use the Save a Copy option and set it to EPS.

Stephen Ray